When we meet the first ‘hard evidence’ of our ANBOs in the archeological record? So the first ‘hard evidence’ of the use of fire and of the making of stone tools for cutting and scraping?

For the first use of fire the mainstream paleos can only find evidence in caves. But there is no indication that the ANBOs lived in caves, they made their forage trips over the open grass areas and spent the night in tree tops until they could stay on the ground around the campfire. We’ll talk about it further. But even campfires don’t leave an archaeological trace after let us say ten years. And certainly not if the researchers are not looking for it.
Stone tools do. In my texts I could show for years the following sketch in the 2000 article of the Journal of Archaeological Science[1] of the Kada Gona stone tools.

At 15 locations east and west of the Kada Gona river, Ethiopia, Sileshi Semaw and his team recovered more than 3000 surface and excavated artifacts, dated 2.6 –2.5 million years ago. But slaughter sites are not normally places where the slaughterers leave behind fossil remains of themselves!
The paleos suspect that the makers of these well-flaked artifacts are : Australopithecus garhi.
Archaeological name of these earliest stone industry: Oldowan.
Other early Oldowan sites, older than 2 million years ago: Olduvai, Omo, Bouri, Lokalei.

[We are not sure which fossil, if any, belongs to the population of animals that could name things. Brunet, head of the French group which found the 6-7 million year old hominid skull in Chad, is shown with the skull, saying: “It’s a lot of emotion to have in my hand the beginning of the human lineage…” But there is no label on the skull, and it is impossible to know if the skull in his hand is from an ancestor-bonobo, or from a prey of the ancestor-bonobos. If this fossil is found in context with fossil remains of prey animals, thus in context of a slaughter place, then one may see this skull as a prey[2].]

All these 2.5 million years old artifacts on the image were found together with animal bones, many of them with stone-tool cut-marks. For us, these Kada Gona tools were longtime the hallmark of the second big jump of our ancestors, as the consequence of the first jump: names for the things. Was it the climate again that triggered the jump?

For five million years, the climate had been stable without giving much reason for changing behavior. But 2,5 mya the Ice Ages, the periodical increase of ice caps on the poles and around the high mountains, began. From now there were cold periods (stadials, maxima) interspersed with warm periods (interstadials, minima).
By 2.5 mya it started with a dramatic cooling and drying. Jungles receded to a narrow and interrupted belt around the equator; savannahs turned into deserts. There were ever less trees to sleep in, ever more natural fires.

I said: “the Kada Gona tools were the hallmark” … until a more recent publication[3] about cut-marks on bones from the Dikika site in Ethiopia demonstrates that stone ‘knives’ for processing of bones of scavenged carcasses may have been used much earlier: 3,4 million years ago.

Butchery tools: the cut-marks on the bones are the result of “hunting and/or aggressive scavenging of large ungulate carcasses”.
So the butchering of carcasses with stone tools must have preceded the start of the Ice Ages.

And who butchered? Even today (Inuit) it is the women who butcher the spoils brought in by the men! This division of tasks may already be so ancient. All the more reason to consider the refining of stone tools as a woman’s skill.

Names for the things may have preceded this manufacturing of stone tools if we take some recent experiments with groups of students in learning to manufacture stone tools seriously. One group was only showed stone tools, cores and flakes. The second group got the same basic material but also a skilled toolmaker, showing his skill without words. The third group got all of the second group but now with verbal guidance of the toolmaker.
Needless to say that the last group was the fastest in getting hold of the tool manufacturing.